#include <bits/stdc++.h>
using namespace std;

long long gcd(long long x, long long y)
{
    if (y == 0)
        return x;
    return gcd(y, x % y);
}

long long lcm(long long x, long long y)
{
    if (x == 0 || y == 0)
        return 0;
    return x / gcd(x, y) * y;
}

int main()
{
    const int N = 3;
    vector<pair<int, char>> H(N);
    for (int i = 0; i < N; i++)
    {
        int h;
        cin >> h;
        H[i] = pair<int, char>(h, 'A' + i);
    }
    sort(H.begin(), H.end(), ::greater<pair<int, char>>());
    for (int i = 0; i < N; i++)
    {
        cout << H[i].second << endl;
    }
}